Inflatable fabric segment of curved configuration and the method of making the same



May 1, 1956 P. MAUNEY ET AL 2,743,510 INFLATABLE FABRIC SEGMENT OFCURVED CONFIGURATION AND THE METHOD OF MAKING THE SAME Filed 061.. 19,1955 FIG. I

IO l8 COATING 8 FABRIC OF UNTREATED 9 SYNTHETIC THREADS TIE THREADS FIG.3

/7|5 UNTREATED 0R RAW lo SYNTHETI THREADS D 2?? coAnNG FABRIC OF TREATEDc SYNTHETIC THREADS H TREATED SYNTHETIC THREADS BOTH DIRECTIONS FIG. 4

IN VEN TOR.

- 'ATTDRNEY FIG. 5

United States Patent" INFLATABLE FABRIC SEGMENT OF- CURVED-CONFIGURATIONv AND THE METHOD OF THE SAME Paul: Mauney, Kings Mountain,N. (3., and Charles. J.

ForrLLake Cable, Canton, Ohio, assignors, by mesneassignments, to TheGoodyear Tire & Rubber Com-- pany, a corporation of Ohio ApplicationOctober 19, 1953', Serial No, 386,830

' 3 Claims. (Cl. 2&44

The presentinvention pertains to an inflatable fabric segment orstructural element and the process for making theisame. Moreparticularly, the invention; is concerned with a-method' of fabricationas well as a form of infiat-" able; structure made in. accordance with.the method entirely from fabric which has been coated or treated torender'it impervious to gas and which is'capable ofi assuminga curvedconfiguration upon inflation.

For certain specific uses of more or less temporary nature, structuresfabricated from water-proofed canvas orrubbenzed fabrics and having theability to be quickly. an'd'easilyv constructed and dismantled haveproven' highly advantageous. Such conventional structures, however,usually require some means by. whichthe canvas on fabric is:suspended orsupported in the form which it is tonssuni'e, depending upon the use towhichit is put. supports are usually rigid and often quite bulky, as aresult of. which they are exceedingly diflicult to handle,

store, and transport. In addition, such supporting or sus problemsencountered in the aforementioned conventional.

structures. Moreover, the product of the present invention possesses thefeatures of rigidity and ease of storage and erection not found in theordinary forms of structure.

There are many places where not only avoidance of rigid supporting meansis desirable, but also curved or cylindrical surfaces can be employed tobetter advantage than flat or planar surfaces which must necessarily beangularly joined together to form most structures. The curvedconfiguration of the fabric segment or structural element disclosedherein is highly advantageous in avoiding sharp or angular joints. Thecurved configuration of the fabric segment moreover affords a highlyadvantageous structural shape which possesses greater strengthcharacteristics.

Thus, it is an object of the present invention to provide a form ofinflatable fabric segment or structural element which possesses theaforementioned attributes by reason of its ability to assume a curvedconfiguration upon inflation.

It is a further object of the present invention to provide a method offorming an inflatable fabric segment or structural element characterizedby a curved configuration on inflation.

Other objects and advantages of the product of the invention will becomeapparent as a detailed description of one embodiment of the inventionproceeds.

Fig. 1 of the drawings represents a vertical crosssection through aninflated flat fabric segment illustrating a form of conventionalstructural element.

Fig. 2 illustrates a vertical section through a typical These extent ofcurvature being readily controllable.

curved: fabric segment embodying the teachings: of the present:invention.

Fig: 3 is an enlarged fragmentary section corresponding generallytothat'shown in Fig.v 1.

Fig. 4 is a fragmentary plan view of the top: ply of" thefabri'csegment.

Fig;:5 corresponds to Fig. 4., but illustratesthebottom.

fabric.- plyof the fabric segment.

In: Fig. 1 of the drawings is shown one form of fabricsegment,.indicated generally by the reference; numeralv 1,

constructedfrom. two spacedplies of fabric 2. and 3.whichz.

arejoined together in the weaving operation by means of a plurality ofdrop or tiegthreads 4; The fabric segment 1 is conveniently formed intoan envelopeby joining-the.-

ends and' edges of the fabric plies 2 and 3 as by means ofathetapes 5and 6 which are securely. cemented-'inplace about the entire peripheryof the fabric segment'l.

The-outer or exposed surfaces of. the fabric plies 2 and 3' arecustomarily coated with some suitable gas imper vious coating'such, forexample, as natural or synthetic.

rubber and the like. The tapes 5 and 6'which cooperate.

with thefabric plies 2 and 3 to form an envelope are made from. a fabricwhich has been previously coated:

with. rubber or impregnated witha material whichwill serve to retainygasunder pressure in the chamber'7 of .the'fabric segment 1. 'Although manyother coating and. impregnating materialsare known and couldbe' used.

for. the purpose of rendering the walls of the fabric seg:

ment imperviousto gasunder pressure, thercoatingwhich.

possesses: all the desired characteristics and. has been chiefly.employed is rubber or'synthetic origin.

' For. many purposes, the flat'form of fabric segment" hascertainzdisadvantages as we have already seen. To

overcome these disadvantages, the fabric segment 8 of Fig. 2, comprisinga top fabricply 9 and a bottom fabric ply 10; has been devised. Thefabric segment8 allows for extensibilityv of thetop ply 9 along thelargerzradius ofithecurved sectionand is characterizedby a smoothly.curved: configuration. upon inflation with the degree or Heretofore, inorder to produce a curvature in a flat fabric segment such as thesegment 1, it has been the practice to take a series of folds or tucksin the fabric ply 3 along the smaller radius of the desired curvedsection. Such folding or tucking creates a break line in the fabricsegment 1, tending to weaken it and frequently interferes with thefreedom of the tie threads 4 and, as a result, does not produce asatisfactorily smooth curved section.

Referring to the fabric segment 8 of Fig. 2, the fabric top ply 9 iswoven from warp and weft threads 11 and 12, respectively, which are ofuntreated synthetic origin such, for example, as raw nylon which has notbeen tensilized, so that'when subjected to heat and tension, will extendor stretch. The fabric bottom ply 10 is woven from threads 13 and 14which are of tensilized nylon and have been rendered substantiallyinextensible before being converted into the fabric. The bottom ply 10which is joined to the top ply 9 in the weaving operation by a largenumber of drop or tie threads 15 which are also substantiallyinextensible.

After the fabric top and bottom plies 9 and 10 joined by the tie threads15 have been fabricated, the outer surfaces of the plies are coated withsome suitable gasimpervious coating 16, 17 such, for example, as naturalor synthetic rubber and the like. Next, the edges and ends of the fabricsegment 8 are joined together by the tapes 18 and 19 of coated or rubberimpregnated fabric to form a gas-impervious envelope enclosing thechamber 20 as shown in Fig. 2. Many different forms of coating andimpregnating material maybe used for the purpose of rendering the wallsof the completed fabric segment 8 substantially completely impervious togas under pressure.

Patented May 1,. 1956 and 'may be of either-natural."

3 Rubber of either natural or synthetic origin has proven mostsatisfactory as a coating material.

The completed fabric segment 3 is then inflated and subjected to heat inthe range of approximately 275 to 300 degrees Fahrenheit, at which thecoating material, in this instance, rubber, is set or vulcanized. Thistemperature range corresponds generally to the softening point for theuntreated synthetic threads 11 and 12 from which the top ply 9 of thefabric segment is fabricated. Thus, the temperature and pressure coactto soften the untreated threads 11 and 12 and cause them to extend orstretch while the treated threads 13 and 14 in the bottom ply of thefabric segment}; remain unaffected.

With the anchoring effect produced by the fabric construction embodyingthe substantially inextensible threads 13 and 14 of the bottom ply 10and tie threads 15, the extension of the top ply 9 will cause the fabricsegment 8 to assume the smooth curved configuration illustrated in Fig.2. The fabric segment 8 is capable of assuming the predetermined degreeof curvature originally imparted to it. it may be originally formed intoa cylinder or any intermediate arcuate form of structure, if desired.These forms of fabric segments afford greater rigidity and strengthcharacteristics without sacrificing the adaptabil ity of the material.

Whenever the gas is released from chamber 20 of the fabric segment 8through a tube or conventional valve unit (not shown) which may take theform of a tire inflating valve, the entire element will collapse into aconveniently small and compact bundle. This structure with its curvedconfiguration is capable of extensive use in all types of temporarybuildings, shelters, forms, flotation elements, supporting structures,and the like.

While certain representative embodiments and details have been shown forthe purpose of illustrating the invention, it will be apparent to thoseskilled in this art that various changes and modificationsmay be madetherein without departing from the spirit or scope of the invention.

We claim:

l. An inflatable fabric segment capable of assuming a curvedconfiguration upon inflation, said fabric segment comprising a doubleply construction in which the plies are substantially superposed andjoined together by a plurality of substantially inextensible tie threadswoven partially into each of the plies for restricting the extent ofseparability of the plies, one of said plies being woven from untreatedraw nylon threads and the other being woven from treated andpre-stressed nylon such that on being subjected to heat and pressure,the first ply will be stretched and the other will remain unaffected;and a vulcanized rubber coating applied to the outermost surfaces ofeach ply.

2. The method of making an inflatable fabric segment capable of assuminga curved configuration upon inflation comprising the step of weaving adouble ply fabric in which the plies are disposed in substantiallysuperposed relation, being joined together by a plurality ofsubstantially inextensible tie threads woven partially into each of theplies, one of said plies being formed of threads which, when subjectedto heat and tension, will stretch to a predetermined extent and theother being formed from prestretched threads incapable of furtherextension; coating the outermost surfaces of each ply with a gasimpervious coating; and inflating the double ply fabric segment andsubjecting to heat while inflated to set the coating and simultaneouslystretch the previously unstressed ply of fabric, whereby a segment ofcurved configuration is formed.

3. The method of making an inflatable fabric segment capable of assuminga curved configuration upon inflation comprising the step of weaving adouble ply fabric in which the plies are disposed in substantiallysuperposed relation, being joined together by a plurality ofsubstantially inextensible tie threads woven partially into each of theplies, one of said plies being formed of untreated and unstretched nylonthreads and the other being formed of prestretched nylon; coating theoutermost surfaces of each ply with a vulcanizable rubber; andvulcanizing the coating and simultaneously subjecting the nylon to heatand tension, whereby a segment of curved configuration is formed.

References Cited in the file of this patent UNITED STATES PATENTS2,197,896 Miles Apr. 23, 1940 2,459,545 Schultz Jan. 18, 1949 2,474,124Schultz June 21, 1949 2,657,716 Ford Nov. 3, 1953

